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Bit of a long shot, but would anyone know of a method of generating multiple sine waves that is faster than using a giant lookup table (where pointers traverse in different step sizes)? It wasn't a performance issue until I tried to build a 64-oscillator additive syntheiser. Currently the CPU usage goes upto about 85%.
A few questions if you please :)
Are you processing wavedata as integers, floats or something else?
What is the huge lookup table you're describing?
What target CPU are you aiming for?
Is threading an option you'll consider?
Here's an interesting observation.
I did a quick test, simulating the creation of a stereo waveform using two vectors for each channel, assuming floats for each sample at 44.1Khz, and created 64 stereo sinwaves using the default CRT sin function and a few floats to indicate the frequency of each of the waves.
On a 2Ghz AMD 32bit CPU that took about 25% CPU duty for realtime, best guess as I could see. Said another way, letting the routine run full speed completed the waveform of 50 million samples about 5.5 times faster than realtime.
This is a crude observation - I'm not sending data to a soundcard, nor dealing with amplitude, etc.